Controlling the wetting properties of surfaces has been the subject of scientific investigation. Most existing hydrophobic surfaces rely on low surface energy polymers, such as fluoroalkylsilane, or patterned roughness at low length scales. Both strategies have significant drawbacks. For example, fluorinated polymers lack resistance to abrasion and are easily degraded by ultraviolet light. Similarly, high roughness coatings are often fragile and poorly suited for harsh environments. In addition, these coatings often rely on complex manufacturing techniques that are not easily scalable.
Aircraft, automotive, and other transparency applications provide additional challenges. For these applications, a hydrophobic coating should maintain high hardness, optical transparency, and resistance to attack by acids and bases. Moreover, because these applications often involve thermally and chemically tempered glass, which rapidly loses its strength at temperatures of 500° C. or higher, it is desirable to have a coating formulation having a cure temperature within the safe limits of glass substrate melting or de-tempering.
It should be appreciated that there is a need for a scalable method of applying an improved hydrophobic coating having environmentally robust hydrophobicity. The improved coating should be robust to environmental degradation, mechanical abrasion, and repeated stress, while exhibiting inherently low surface energy without additional surface patterning. For applications involving, for example, transparent, tempered glass, the coating should maintain hardness, optical transparency, and resistance to attack by acids and bases, while having a cure temperature within the safe limits of glass substrate melting or de-tempering. The present invention fulfills these needs and provides further related advantages.